Study On Vehicle Diesel Performance Of Multiple Injection

By the end of2012, China's civilian vehicle population has reached120million,while the global vehicle population has exceeded1billion. While the mushroomingvehicle provide people with great convenience, it also become a heavy burden to theenvironment. To protect the environment, the world have been developing a series ofmore stringent emission regulations. A large number of studies have shown thatmultiple injection technique is an effective means of reducing harmful engineemissions. The main research works as the following points:Firstly, the high-pressure common rail diesel engine simulation model isestablished on GT-Suite software. By comparing the simulation value and theexperimental value in certain operating condition, verify the accuracy of the model.The results indicate the model is suitable for future research work.Secondly, basing on the simulation results, the paper studies the influence of bothdiesel engine performance and emissions caused by different injection pressure. Theresults shows that improved fuel injection pressure can improve engine power andeconomy, but not solve the emissions.Then, the paper studies the engine performance and emissions impaction causedby different pilot injection quantity and the interval between pilot injection and maininjection. By balancing the power index and economic index as well as emissionsperformance under the various injection programs, the optimum parameters isdetermined ultimately in particular operating condition. The results shows that settingreasonable pilot injection parameters can effectively reduce emissions of both NOxand soot; unreasonable parameters have a bad effect on emissions: With the increaseof the interval between pilot injection and main injection and soot emissions decreases;NOx emissions increases after decreases at first and then decreases. With the increaseof the pilot injection quantity, NOx emissions increases while soot emissions reduces.The paper selects the pilot injection quantity of5%, the interval between pilotinjection and main injection of10°CA as the best combination under the operatingcondition.This study has a certain of reference value to further research on multipleinjection diesel engine technology. Because of limited time, the article optimize thefuel injection strategy in one operating condition,and follow-ups can determine thefuel injection Map in whole condition by using the same method, which will docontribution to the high-pressure common-rail diesel engine design.